Background: Whether recreational cannabis legalization is associated with changes in alcohol consumption (suggesting a potential substitution or complementary relationship) is a key question as cannabis policy evolves, particularly given the adverse health and social effects of alcohol use....

Each year, 10,000 individuals die in alcohol-impaired traffic accidents in the United States, while psychoactive drugs are involved in 20% of all fatal traffic accidents. We investigate whether state parity laws for substance use disorder (SUD) treatment have the unintended benefit of reducing...